[Si:1]([O:8][CH2:9][C@@H:10]1[CH:15]=[CH:14][C:13](=[O:16])[CH2:12][N:11]1[C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].O.C(=O)([O-])[O-].[K+].[K+].[I:31]I>CN(C)C1C=CN=CC=1.C1COCC1.CCOCC>[Si:1]([O:8][CH2:9][C@@H:10]1[CH:15]=[C:14]([I:31])[C:13](=[O:16])[CH2:12][N:11]1[C:17]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]To a solution of (S)-tert-butyl 2-((tert-butyldimethylsilyloxy)methyl)-5-oxo-5,6-dihydropyridine-1(2H)-carboxylate (Intermediate 50, 10 g, 29.28 mmol) and 4-dimethylaminopyridine (0.894 g, 7.32 mmol) in THF (100 mL)/water (100 mL) at room temperature was added potassium carbonate (3.24 g, 23.42 mmol) and iodine (8.92 g, 35.14 mmol). After stirring for 15 minutes, the reaction mixture was diluted with ether and washed with saturated sodium thiosulfate twice, then 5% citric acid and brine. The organics were dried over magnesium sulfate, filtered and concentrated. Silica gel chromatography (0%-15% ethyl acetate/hexanes) afforded the desired product as a tan oil (11.6 g, 85%).
Wird geladen…